8 amp 1 in. corded sds-plus concrete/masonry avt rotary hammer drill with 4-1/2 in. corded angle grinder with hard case the makita 1 in. avt rotary hammer (model the makita 1 in. avt rotary hammer (model hr, with d-handle) is engineered with anti-vibration technology (avt), an internal counterbalance system for significantly less vibration. the hr combines performance and power.80 product ratings - bosch vsr 8 amp 1 sds-plus bulldog xtreme corded rotary hammer drill-new $132.00 trending at $153.98 trending price is based on prices over last 90.